<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>
          body{
              height: 4000px;
              background-image: url(images/sms.jpg);
              background-repeat: no-repeat;
              background-position: center top;
              /* 背可以滚动 */
              /* background-attachment: scroll; */

              /* 背景固定不能滚动 */
              background-attachment: fixed;

          }
          p{
              font-size: 50px;
              color: green;
          }
    </style>
</head>
<body>
    <p>111111111111</p>
    <p>111111111111</p>
    <p>111111111111</p>
    <p>111111111111</p>
    <p>111111111111</p>
</body>
</html>